OSD3358 not booting from SD card on custom board design

[Manish]

Hi,

I am working on a OSD3358 custom board, the reference design is from Pocket beagle, I am not sure where the problem is. This is the first time I’m designing for the OSD3358 Chip.

I have tried both the methods mentioned in the forum posts #4733 and #4608 regarding the EEPROM ID check. Still I am unable to boot.The image I am using – AM3358 Debian 10.3 2020-04-06 4GB SD IoT and even nothing is showing up on UART 0. This led me to further review the design of my board.

I have a few doubts regarding my design , It would be of great help to review my design before proceeding further on the design changes. This is my github link : https://github.com/Manish-0521/osd3358.git

1. Maybe the Trace width of SD card lines in the PCB design is wrong, I have attempted on making it Single Co-Planar 50 OHM impedance.

2. I am turing the device on from the USB and the Trace width of VIN_USB is less in my design, as per the forums i have noticed that due to Inrush Current of 1.5A there might be an issue. I am getting the correct voltages on the Test points VDDS_DDR, VDD_CORE, VDD_MPU, VDDS_PLL. So I am assuming the Power is fine. But i did not check the sequence of turning on of these voltages.

Please review the schematics too.

Thanks in advance,
Manish

[Neeraj Dantu]

Manish,

Initial look into the schematics does not reveal anything obviously incorrect. Although 1 thing I noticed was both pull-ups and pull-downs for Address setting of IC1 seem to be populated, which might mess withe EEPROM configuration as EEPROM inside OSD3358-SM is on address 0x50. May not be an issue, but recommend checking and making sure the external EEPROM is on a different address.

If you are getting outputs on power rails, that would mean that the PMIC is up. Can you double check all voltage rails are OK according to https://octavosystems.com/app_notes/osd335x-sm-power-application-note/?

When there is no SD card, do you get “CCCC” output on UART0? If so, this is an indication that the processor has booted correctly and searching for a boot media.

The other things to check is 24MHz and 32KHz clock signals.

One way you can completely bypass EEPROM is by using EEPROM Blank image as described in https://github.com/RobertCNelson/omap-image-builder/tree/master/octavo. You can build this image on your machine by selecting octavo-blank-eeprom.conf while running https://github.com/RobertCNelson/omap-image-builder/tree/master/octavo#generate-image-file.

When booting with the SD card, you should be able to see activity on SD CLK and CMD lines, if you have an oscilloscope, this would be a debug step to understand whether the processor is attempting to boot from the SD card.

Please let us know if you have an update on the debug,

Best,

Neeraj

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